碳黑对苯乙烯自由基聚合反应影响的研究

研究了碳黑对苯乙烯单体聚合物反应的影响，结果表明，用过氧化苯甲酰作引发剂，普通碳黑子对苯乙烯的聚合有强烈的阻聚作用，而用偶氮二异丁腈引发聚合物时，普通碳黑的阻聚性很小，当时碳黑进行接枝处理后，接枝碳黑对苯乙烯自由基聚合的影响程度与接枝方法有关，其中过氧化苯甲酰 自由基枝枝碳黑的聚性变化较大。     

Electro-copolymerisation of indene and styrene

Electroinitiated cationic copolymerisation of indene and styrene was investigated by constant potential electrolysis. Effects of copolymerisation potential and temperature on the copolymer composition and the reactivity ratios are discussed. The reactivity ratios of the monomers were calculated according to the integrated Lewis-Mayo equation.     

Complex formation of montmorillonite clay with polymers. Part 2: The use of montmorillonite clay–vinyl monomer complex as a comonomer in the copolymerization reaction of styrene–acrylonitrile monomers

The bulk copolymerization of styrene–acrylonitrile monomers using styrene‐N⁺–montmorillonite complex as a comonomer in the polymerization was studied. The X‐ray diffraction (XRD) analysis showed that part of the styrene‐N⁺–montmorillonite complex remained non‐dispersed (immiscible) and the copolymer was excluded from the interlayer of the immiscible part of the clay. The successive chemical extraction process revealed that a reasonable amount of the styrene–acrylonitrile copolymer was directly attached to the styrene‐N⁺–montmorillonite complex and enveloped the clay. Highly exfoliated clay lamella and nanospheres (3–5 nm) were observed by transmission electron microscopy (TEM). The montmorillonite clay assume two different morphologies, immiscible and exfoliated, on the basis of the XRD and TEM data. A simple method of calculation of the ratio of the exfoliated/immiscible amounts of the clay indicated that the amount of the styrene‐N⁺–montmorillonite complex exfoliated into separate lamella was 40 % (w/w) of the amount of the clay samples containing 2 % of the (styrene‐N⁺–montmorillonite complex) clay. This amount of exfoliated clay decreases with the increase of the concentration of the clay. The presence of the styrene‐N⁺–montmorillonite clay in the copolymerization reaction had a minor effect on both the copolymer composition and the molecular weight. Modification of the clay with the derivatized styrene monomer can achieve a nanocomposite using a percentage no more than 4 % (w/w) of complex in the copolymer. Copyright © 2004 Society of Chemical Industry     

苯乙烯与1-(2-叔丁基过氧异丙基)-3-异丙烯基苯共聚行为研究

苯乙烯与1－（2－叔丁基过氧异丙基）－3－异丙烯基苯（D120）能进行自由基共聚合反应，聚合后过氧基团以侧基的形成被保留在共聚物大分子链上，凝胶色谱分析发现，随原料单体中D120比例增加，共聚物的分子量减小，分子量分布变窄，DSC分析发现共聚物中过氧基团的分解温度随D120结构单元含量的增加而下降，但仍高于D120单体过氧基团的分解温度，苯乙烯与D120的竞聚率为：rD120=0.700,rSt=0.714。     

Decreasing miscibility with greater heterogeneity in ternary polymer blend: poly(cyclohexyl methacrylate), poly(α‐methyl styrene) and poly(4‐methyl styrene)

A ternary blend system comprising poly(cyclohexyl methacrylate) (PCHMA), poly(α‐methyl styrene) (PαMS) and poly(4‐methyl styrene) (P4MS) was investigated by thermal analysis, optical and scanning electron microscopy. Ternary phase behaviour was compared with the behaviour for the three constituent binary pairs. This study showed that the ternary blends of PCHMA/PαMS/P4MS in most compositions were miscible, with an apparent glass transition temperature (T_g) and distinct cloud‐point transitions, which were located at lower temperatures than their binary counterparts. However, in a closed‐loop range of compositions roughly near the centre of the triangular phase diagram, some ternary blends displayed phase separation with heterogeneity domains of about 1 µm. Therefore, it is properly concluded that ternary PCHMA/PαMS/P4M is partially miscible with a small closed‐loop immisciblity range, even though all the constituent binary pairs are fully miscible. Thermodynamic backgrounds leading to decreased miscibility and greater heterogeneity in a ternary polymer system in comparison with the binary counterparts are discussed. © 2003 Society of Chemical Industry     

Preparation and characterization of polyurethane microcapsules containing n‐octadecane with styrene‐maleic anhydride as a surfactant by interfacial polycondensation

A series of polyurethane microcapsules containing a phase change material (PCM) of n‐octadecane was successfully synthesized by an interfacial polymerization in aqueous styrene‐maleic anhydride (SMA) dispersion with diethylene triamine (DETA) as a chain extender reacting with toluene‐2,4‐diisocyanate (TDI). The average diameter of microPCMs is in the range of 5–10 μm under the stirring speed of 3000–4000 rpm. Optical and SEM morphologies of microPCMs had ensured that the shell was regularly fabricated with the influence of SMA. FTIR results confirmed that the shell material was polyurethane and the SMA chains associated on core material reacted with TDI forming a part of shell material. The shell thickness was decreasing in the range of 0.31–0.55 μm with the molar ratio of DETA/TDI from 0.84 to 1.35 and the weight of core material increasing from 40 to 80% (wt %). By controlling the weight ratio of PCM as 40, 50, 60, 70, and 80% in microPCMs, it was found using DSC that the T_m and T_c of microPCMs were in the range of 29.8–31.0^oC and 21.1–22.0°C and an obvious phase change had been achieved nearly the same temperature range of that of PCM. The results from release curves of microPCM samples prepared by 1.4, 1.7, and 2.0 g of SMA indicated the release properties were affected by the amount of the dispersant, which attributed to the emulsion effect and shell polymerization structure. The above results suggest that the shell structure of microPCMs can be controlled and the properties of microPCMs determined by shell will perform proper practical usage. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4996–5006, 2006     

乙苯/苯乙烯塔分离效率问题的技术分析及整改措施

分析了齐鲁分公司200kt/a乙苯/苯乙烯装置乙苯/苯乙烯塔(T-401)分离效率低的原因,即降液管设计偏小,液体在降液管内流速过快,引起液体飞溅;安装分布器使用的石棉垫片溶胀而粉碎后堵塞了分布槽;分布器上使用的垫片脱落形成缝隙而漏液;填料装得不密实,留有缝隙;二级分布槽变形等.针对存在问题提出了相应的整改措施,并考察了整改措施实施效果.结果表明,整改后该塔的分离能力满足了工艺要求,并有一定的操作弹性.     

用两亲聚合物制备大颗粒苯丙乳液

分别以两亲聚合物P(C9-AA)和P(DCPD-St-α-St-AA)作乳化荆，研究了制备大颗粒(约1μm)及具有一定稳定性的苯丙乳液的方法，讨论了乳化剂，温度及引发剂用量对乳液性能的影响。结果表明，以P(C9-AA)作乳化剂时，引发剂用量为单体质量的1．2％，90℃时可以合成性能良好的苯丙乳液；以P(DCPD-St-α-St-AA)作乳化荆时，引发剂用量为单体质量的1．2％，80℃时可以合成性能良好的苯丙乳液。     

Taste recognition threshold concentrations of styrene in oil-in-water emulsions and yoghurts

Taste recognition threshold concentrations (TRTC) of styrene were determined in samples of oil-in-water emulsions (30–300 g kg^?1 oil) and yoghurts (1–30 g kg^?1 fat), spiked with styrene. The observed TRTC increased linearly with increasing fat content and ranged from 0–3 to 2–1 mg kg^?1 for the emulsions and from 36 to 171 g kg^?1 for the yoghurts. Styrene equilibrium partition coefficients between emulsions and their respective vapour phases were determined. The concentrations of styrene in the continuous aqueous phase of the emulsions and yoghurts were calculated at the TRTC. The styrene concentrations in the continuous phase had constant values of about 15 g kg^?1 indicating that perception of styrene for oil-in–water emulsions is determined by the aqueous phase of the emulsion. The concentrations of styrene in the vapor phases above the emulsions and yoghurts were also calculated and were found to be constant at the TRTC. This relationship probably resulted from the equilibrium of distribution of styrene between the respective phases. Commercial yoghurt packed in polystyrene beakers contained styrene levels in the range 2–11 g kg^?1, much lower then the TRTC reported.     

Radiation polymerization of acrylonitrile in a viscous system with styrene

Radiation polymerization of acrylonitrile in a viscous system with styrene was performed at ambient temperature by using γ‐rays. It is found that the overall rate of polymerization was accelerated after critical conversion due to the gel effect. As the molar fraction of styrene in monomer feed (f_St) is increased, both the total polymer conversion and molar fraction of acrylonitrile in the copolymer feed (F_AN) were decreased. The monomer reactivity ratios for acrylonitrile and styerne were determined to be r₁ (AN) = 0.25 and r₂ (St) = 2.0, respectively. The copolymers obtained were characterized by Fourier transformed infrared spectra (FTIR), X‐ray diffraction (XRD), scanning electron microscopy (SEM), ¹H‐NMR, and pyrolysis mass spectrometry (PMS). It was found that the slight addition of styrene to acrylonitrile strongly changes crystallinity, morphology, and thermal decomposition of the resulting polymer. ¹H‐NMR measurment of AN/St copolymer showed the appearance of aromatic proton signals and shifted the resonance of the methylene proton to lower chemical shifts. The mass spectra of AN/St copolymers showed fragments of pyrolysates corresponding to oligonitriles with styrene end groups. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 268–275, 2002; DOI 10.1002/app.10324